What the evidence tells us about Tylenol, leucovorin, and autism - STAT News

This article by STAT examines the scientific evidence behind two autism-related claims highlighted by President Trump and RFK Jr.: whether Tylenol use during pregnancy increases autism risk and whether leucovorin can improve verbal abilities in people with autism.

The piece explores the ongoing scientific debate around Tylenol and autism, with researchers divided on whether correlations represent true causation. While some studies show mothers taking acetaminophen during pregnancy have higher rates of children with autism, a major Swedish study suggests this may be due to genetic factors rather than the medication itself. The research indicates that people genetically predisposed to autism may also experience more pregnancy pain, leading to increased painkiller use.

• Multiple studies show correlations between prenatal Tylenol use and autism, but debate continues over whether this represents causation or confounding factors
• A large Swedish sibling study suggests genetic predisposition may explain the association rather than the medication directly causing autism
• Small studies indicate leucovorin may modestly improve verbal abilities in children with autism, but larger trials are needed for definitive evidence
• Both medications lack extensive research due to their generic status, making it difficult for manufacturers to justify funding large-scale studies